PIONIC DOUBLE-CHARGE-EXCHANGE ON NB-93 AT LOW ENERGIES

The reaction Nb-93(pi(+),pi(-))Te-93 has been measured in the energy r ange T-pi = 30-60 MeV at various scattering angles. At all energies th e groundstate transition could be observed, whereas the transition to the double isobaric analog state has been identified unambiguously onl y at T-pi = 50 MeV. The groundstate transition exhibits a pronounced r esonance-like energy dependence which extends the systematics of this peculiar feature to heavy nuclei. An explanation within the d' hypothe sis is presented. (C) 1998 Elsevier Science B.V. All rights reserved.